Aim

You are required to develop a shell and a clock for OSx311. Your work should meet the specifications below:

Clock

After booting up, your OS should display clock on the screen. Below are the requirements for the clock:

• After booting, the time will be 00:00:00 initially.
• Clock should stay on the top right corner of the screen no matter what
• Clock updates should be seamless, erratic increments are not acceptable
• Clock updates should be performed using the timer interrupt, using a dummy loop for updating the clock is absolutely unacceptable
• Clock should be in 24-hour format
• Single digit hour, minute, second values should be zero padded

Command Shell

Your operating system should provide users a shell that can run commands. Shell should meet the specifications below:

• At the very least, "help" and "settime" commands should be supported
• If an invalid command is entered, the user should be encouraged to use help
• help command should provide the user a list of available commands
• settime command should update the CMOS RTC with the value entered (clock should continue from the new time)
• If any command is called with invalid parameters, the user should be presented with the correct usage
• It is your responsibility to mind the number of spaces entered between parameters
• reboot command should return the OS to its initial state

Colors

Welcome message: red over black
Clock face: black over white
Command prompt: green over black
Anything else: white over black

This is more or less how your OS should look like:

Other Information

For color codes, RTC registers etc. you can refer to these sites:

• HelpPC
• OSDev
• kb.c

Hint: